TUESDAY, Sept. 28, 2004 (HealthDayNews) -- Women with early ovarian cancer may benefit from chemotherapy in addition to surgery.
It's not clear, however, which women would most benefit, or which exact treatment would be most beneficial, said a survey of existing data appearing in the Nov. 1 issue of Cancer.
Slightly more than one-quarter (27 percent) of ovarian cancers are caught while they are still confined to the ovaries. At this stage of the disease, women have a five-year survival rate of about 85 percent.
Many doctors prefer not to add chemotherapy, as surgery turns out to be enough for 80 percent of patients with early-stage ovarian cancer.
The problem, however, is knowing for sure what stage the cancer is in -- that is, the tumor's size and whether it has advanced from the original affected organ. Staging for ovarian cancer is done surgically, during the primary operation to remove the tumor, and it is often not done consistently well.
"Certainly, pathological staging done at the time of surgery is a lot more reliable than a series of CAT scans or something else, but they're not always done correctly," said Dr. Greg Bizette, a medical oncologist at the Ochsner Clinic Foundation in Covington, La. "It depends on who's doing this kind of surgery. The approach of a garden-variety gynecologist might not be the same as a gynecologic oncologist who's used to doing these things."
One study showed that a second surgery to stage the disease put 25 percent of women in a more advanced stage than originally thought, and that 70 percent of these were upstaged to stage III, a far more serious condition. When the disease is this far along, chemotherapy is recommended as a routine part of treatment.
For this reason, other physicians feel that adding chemotherapy is important because only 10 percent of women who are thought to have stage I disease actually get adequate surgical staging.
Given this large gray area, the Gynecologic Cancer Disease Site Group of Cancer Care Ontario decided to conduct a meta-analysis of randomized controlled trials published since 1965.
Thirteen such trials were identified which compared different therapies (over and above surgery) for women with stage I ovarian cancer.
Overall, the trials indicated about a 35 percent increased chance of survival for stage I patients and a 30 percent lower risk of the disease recurring for women who had had chemo vs. those who had not. Platinum-based chemotherapy, which is standard treatment, improved overall five-year survival by about 8 percent in absolute terms.
These trials had many of the problems encountered in the real world -- namely, not all of them were comparing apples and apples. Eight of the trials looked only at women with stage I ovarian cancer. Most of the trials did not show adequate staging, and there was insufficient data on the dose, duration and optimal regimen (the number of cycles) of the chemotherapy.
These problems highlight the need for better randomized controlled studies and, specifically, ones that use a standard staging procedure, said study author Dr. Laurie Elit, an associate professor of obstetrics and gynecology at McMaster University in Hamilton, Ontario.
In the meantime, Elit and her colleagues recommend that women with suspected ovarian cancer receive surgical staging. Those who have received optimal staging and whose tumors show good prognostic factors will probably do well without chemotherapy. Women who do not get optimal staging and who may have more advanced tumors should receive platinum-based chemotherapy.
"The conclusions are similar to those of previous studies," said Dr. Kevin Holcomb, director of gynecologic oncology at Beth Israel Medical Center in New York City. "This study shows that women who are optimally staged and have stage 1/grade 1 tumors have an excellent prognosis without adjuvant chemotherapy."
Post-surgery chemotherapy, he added, appeared to be "most beneficial for patients with inadequate staging. Therefore, adequate staging is crucial in determining which patients will truly benefit from adjuvant chemotherapy."
The question, though, is still somewhat open. "When you look at early-stage ovarian cancer, there aren't oodles and oodles of cases that we find in that stage," Bizette said. "It would take years to accrue the number of patients necessary to detect a small percentage benefit of doing the chemotherapy."
More information
The National Cancer Institute has more on ovarian cancer.
